Recent years have seen an increased interest in field emitter displays. This is attributable to the fact that such displays can fulfill the goal of consumer affordable hang-on-the-wall flat panel television displays with diagonals in the range of 20 to 60 inches. Certain field emitter displays, or flat panel displays, operate on the same physical principle as fluorescent lamps. A gas discharge generates ultraviolet light which excites a phosphor layer that fluoresces visible light. Other field emitter displays operate on the same physical principals as cathode ray tube (CRT) based displays. Excited electrons are guided to a phosphor target to create a display. Silicon based field emitter arrays are one source for creating similar displays.
Single crystalline structures have been under investigation for some time. However, large area, TV size, displays are likely to be expensive and difficult to manufacture from single crystal silicon wafers. Polycrystalline silicon, on the other hand, provides a viable substitute to single crystal silicon since it can be deposited over large areas on glass or other substrates.
Polysilicon field emitter devices have been previously described for flat panel field emission displays. But such field emitters have only been produced according to lengthy, conventional, integrated circuit technology, e.g., by masking polysilicon and then either etching or oxidation to produce cones of polysilicon with points for field emitters. The cones of polysilicon can then be utilized directly or undergo further processing to cover the points with some inert metal or low work function material.
Thus, it is desirable to develop a method and structure for large population density arrays of field emitters without compromising the responsiveness and reliability of the emitter. Likewise, it is desirable to obtain this result through an improved and streamlined manufacturing technique.